The former Burnley striker fired his first Premier League goal into the top corner on the stroke of halftime to give Harry Redknapp's men their first win this season.
On the day that QPR manager Harry Redknapp confirmed striker Remy's imminent departure from the club, with a switch to Stamford Bridge apparently due to be completed soon, Austin returned from injury to score the only goal of the game.
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The former Burnley man had missed the 4-0 defeat to Tottenham with a hamstring strain but produced a smart finish in first-half stoppage time to give the London club its first points since promotion back to the top flight.
Even without Remy, who was left out of the squad, Redknapp's side put in its best performance of the campaign so far and could have won more comfortably had Leroy Fer's long-range shot not cannoned back off the crossbar prior to Austin's opener.
Although Sunderland initially improved after the break, in the end the club did not have enough, as Gus Poyet's side struggled to carve out clear-cut chances.
Despite two opening Premier League defeats, Redknapp had received a vote of confidence from club owner Tony Fernandes in the build-up to the match, and he revealed on the eve of the game that he is in discussions to sign a new two-year deal.
He will, however, likely have to plan for the immediate future without Remy, after revealing to television reporters prior to kickoff that the France international is headed for Chelsea.
In Remy's absence, Austin was handed a start in his place.
The former Burnley man almost made a near-instant impact too, when he headed just off target.
Junior Hoilett, one of the few QPR players to impress in the midweek League Cup defeat to League Two Burton, delivered an inviting corner and Austin saw his powerful header cleared off the line by Connor Wickham in the fourth minute.
Sunderland looked just as much of an attacking threat as the host and six minutes later, Steven Fletcher's poked effort forced Robert Green into a desperate save, following Adam Johnson's precise through ball.
Fer nearly broke the deadlock on the half-hour mark in spectacular fashion - the former Norwich man jinking away from Lee Cattermole before striking a ferocious effort from 35 yards that came crashing back off the crossbar.
But, having survived that scare, Sunderland could not hold on until the break.
In first-half stoppage time Fer knocked down a deep corner at the back post and Austin pounced, smashing the ball into the top corner.
Sunderland started the second half with renewed determination and almost scored a leveller soon after the restart.
Patrick van Aanholt's 54th-minute cross was not dealt with by the QPR defence and Santiago Vergini's left-footed strike forced Green into a smart save to his right.
Poyet's side began to enjoy more possession, but they struggled to capitalize as the team lacked a cutting edge in the final third.
The Black Cats did mount some late pressure - with United States striker Jozy Altidore introduced from the bench in a bid to bolster their attacking options.
But it was QPR which really should have wrapped up the win with four minutes left.
Substitute Armand Traore raced through on goal and went one-on-one with Vito Mannone, only for the wing back to drag his right-footed effort wide of the post.